21405826084 has 6 divisors (see below), whose sum is σ = 37460195654. Its totient is φ = 10702913040.

The previous prime is 21405826069. The next prime is 21405826103. The reversal of 21405826084 is 48062850412.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 20380417600 + 1025408484 = 142760^2 + 32022^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2675728257 + ... + 2675728264.

Almost surely, 2^21405826084 is an apocalyptic number.

It is an amenable number.

21405826084 is a deficient number, since it is larger than the sum of its proper divisors (16054369570).

21405826084 is a wasteful number, since it uses less digits than its factorization.

21405826084 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5351456525 (or 5351456523 counting only the distinct ones).

The product of its (nonzero) digits is 122880, while the sum is 40.

The spelling of 21405826084 in words is "twenty-one billion, four hundred five million, eight hundred twenty-six thousand, eighty-four".